Final answer:
Check your Ubuntu VirtualBox machine's network adapter settings, verify the firewall settings allowing ICMP requests, and ensure proper IP configuration. These steps should resolve the issue with being unable to ping the Ubuntu virtual machine.
Step-by-step explanation:
If you are experiencing issues with pinging the Ubuntu operating system in VirtualBox from a Kali host and Windows 10, there are several aspects of the network configuration you should check. Start by ensuring that the network adapter in the VirtualBox settings for Ubuntu is configured correctly. Common settings for networking in VirtualBox include NAT, Bridged Adapter, or Host-only, depending on the desired connectivity.
If Ubuntu can ping the host and other machines, but cannot be pinged, it's possible that the firewall on the Ubuntu machine is blocking incoming ICMP requests. Check the UFW firewall to ensure that it is not preventing pings. Use the command sudo ufw status to check the firewall status and sudo ufw allow icmp to allow ping requests.
Another consideration is the IP configuration within Ubuntu. Ensure that the machine has a proper IP address within the network range and that it's not colliding with other IPs. Additionally, the guest machine's network mode should align with network requirements (e.g., a Bridged Adapter if it needs to communicate with physical network devices).